TSIAKAKA Olivier

PhD student at Sorbonne University
Team : SYEL
https://lip6.fr/Olivier.Tsiakaka

Supervision : Sylvain FERUGLIO

Contribution to the development of a multimodal device for the medical imaging of the spinal cord

The Spinal Cord (SC) is the part of the Central Nervous System (CNS) responsible for the transmission of the sensory inputs and the motor outputs in all vertebrates. It also houses major autonomous functions. SC injuries and other pathologies of the spinal column represent a large cause of disabilities or deaths. After the accute phase, secondary mechanisms are set in motion and affect the functional progonosis of the SC and the depending organs. Conventional imagery tools (MRI, for example) do not provide enough information regarding the physiological consequences of such ravages. This lack of data leads to an uncertainty of the efficacy and the relevance of the medical actions taken toward the recovery of the patient, following surgeries.
Medullar activities, as in the whole body, are characterised by a modification of the local energy supply of oxygen and electrophysiological events. In case of alteration of the CNS, it is opportune to characterise it in real time and quantify the related metabolic variations.
This thesis focuses on the instrumentation of the SC, through the development of an experimental device. It uses the Diffuse Optical Imaging (DOI) technique to quantify the local variations of blood flow. For this purpose, several prototypes were designed and used during animal experiments. An optical characterisation was performed on SC samples, ex vivo and in vivo. We built up on this information, representing a first for the state of art, to establish guidelines for the development of the embedded device in the hostile biological environment. The feasability of the functional monitoring with DOI in the big animal (FBM pig) is now proven. The design methodology is addressed in order to highlight the interdependances between the measurement and the system.
The results are very promising. They open a new path of exploration, complementary to the ones in everyday medical routine. In fine, this approach will be able to give quantitative indicators for the evaluation and the care of medullar pathologies. Destined for hospital praticians first, several purposes may be drawn from this device ranging from orthopedic to vascular surgeries for pets and humans. Researchers may also benefit from such a tool that would help them understand better the SC and its independance regarding the brain.

Defence : 12/12/2018

Jury members :

Mme. LEWIS Noëlle, Professeure des Universités, IMS Bordeaux [Rapporteur]
Mme. LISSORGUES Gaëlle, Professeure des Universités, ESIEE [Rapporteur]
Mme. GORBET Maud, Associate Professor, Université de Waterloo (Canada)
M. KOKABI Hamid, Professeur des Universités, Sorbonne Université
M. PASCAL-MOUSSELLARD Hugues, Professeur des Universités - Praticien Hospitalier, Sorbonne Université - APHP
M. FERUGLIO Sylvain, Professeur des Universités, Sorbonne Université

Departure date : 12/01/2019

2015-2022 Publications